Steam-generator.



3 No. 628,606. Patented July II, I899. 1 J. C. PARKER.

STEAM GENERATOR.

(Application flied Sept. 12, 1898.)

(No Model.)

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UNITED STATES PATENT OFFICE.

JOHN C. PARKER, OF SAN FRANCISCO, CALIFORNIA.

STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No. 628,606, dated July 1899.

Application filed September 12,1898. Serial No. 690,779. (No model.)

To all whmn it nuty concern:

,in especially applicable to the water-tube type.

Said invention consists, primarily, in so constructing and arranging the heating and evaporating tubes of such generators that the areas of their cross-sections will be in proportion to volumes and velocities of the water and steam and in keeping these separate so far as possible throughout the cycle of circulation.

It also consists in separate superimposed drums or chambers for steam and water and check-valves to prevent the flow of the water except in the direction intended.

The objects of my invention are to attain a more effective, safe, and economical operation of watertube steam-generators by main-- taining constantly the full gravity-head of the water to produce circulation, to prevent back pressure and resistance to circulation, to keep separate the steam and water, and to permit the former to rise freely and without disturbing action upon the latter.

To these ends I construct water-tube boilers as illustrated in the drawings herewith, being an improvement on Letters Patent No.

. 608,218, granted to me on the 2d day of August, 1898, for an improvement in steam-generators.

Referring to the present drawing, the figure is a vertical section of a steam-generator or of one unit composing a part of the same constructed and operating according to my invention.

A is a furnace of the usual construction, provided with a front 13, fire-grates O, and a chimney-way D.

E is a steam drum or chamber, and F a similar drum or chamber containing water supplied at V.

T is a check-valve or non-return valve between the steam and water chambers E and F, opening toward the latter. R is a similar check-valve between the water-chamber F and the generating-tubes G, L, M, and O.

a a a a represent bubbles of steam as they are observed to form in transparent evaporating-tubes arranged for experimental purposes.

In the drawing the left or first column of figures indicates approximately the degree of temperature of the water and steam in the tubes. The second column of figures indicates approximately the temperature of the gases of combustion, in both cases by the Fahrenheit scale.

Theoperation of myimproved generator is in essential features the same as in the Letters Patent hereinbefore referred tothat is, the course of the Water in circulating is downward toward the fire from the lowest to the highest temperature in the furnace, the scale of temperature being reversed and evaporation taking place during the descent of the water. The distinction in the present invention is in providing for the free escape of steam by the expansion or increasing size of thegenerating-tubes from the point where evaporation begins, or approximately so, to

the steam-uptake pipes and the steam-chamber at the top, also in means to effectually separate the steam and water, as hereinafter explained. In a steam generator having tubes, as shown in the drawing, the evaporation or change of condition of water into steam when the conditions are normal begins at the tube L, or, for'example, at a temperature of about 387 Fahrenheit in the tubes size the resistance to flow will neutralize to the same extent the gravity-head of the water, and

thus retard circulation, which depends on the force of this head. ,I therefore enlarge the size of the evaporating-tubes from the point where the generation of steam begins or as near that substantially as specified.

2. In a water-tube steam-generator, a wapoint as ascertainable, continuing such enlargement in proportion to the volume and velocities of the water and steam taken together to a point where the water is wholly evaporated in the tube 0, as indicated in the drawing, and continue this maximum size or bore through the uptake steam-pipes P to the steam-chamber E. Any entrained water that may at starting or from any cause in operat- E at once passes through the check-valve T down into the water-chamber F. The water in this chamber is maintained at some predetermined level by the usual means of supply and observation or by automatic means. In case of an oversupply of water or if from any other cause the water should rise too high in the chamber F the valve T closes and prevents the water from entering the steamchamber E. The same conditions applyjo the check-valve R between the pipes G and the water-chamber F, so that the circulation of water cannot from any cause be reversed, but must continue downward, as indicated by arrows in the drawing.

In theory the dimensions of the pipes L M N should gradually increase from the point where the conversion into steam begins to the point where full conversion takes place; but in practice it is sufficient if the pipes are serially increased in bore, as shown, tapered pipes being costly and diflicult of construction.

Having thus explained the nature and objects of my invention and the manner of constructing and operating the same, Iclaim and desire to secure by Letters Patent- 1. In a water-tube steam-generator, a water-chamber, a steam-chamber and steamgenerating tubes of successively-increasing diameter connected with said water-chamber and with each other, forming a continuous downward passage in the fire-space from the cooler to the hotter portion thereof with a direct return-passage to the steam-chamber,

tor-chamber, a superimposed steam-chamber connected with said water-chamber, a checkvalve in said connection between said chambers, opening toward the water-chamber, and steanrgenerating tubes of successively-increasing diameter connected with said waterchamber and with each other, forming a continuous down-ward passage in the fire-space from the cooler to the hotter portions thereof, substantially as specified. ing pass up the pipe P and into the chamber 3. In a'water-tube steam-generator, a water-ohamber, a superimposed steam-chamber connected with said water-chamber,a checkvalve in said connection between said chambers opening toward the water-chamber, a tubular passage-way connected with said water-chamber leading continuously downward from the cooler to the hotter portion of the fire-space, a check-valve in said connection between said water-chamber and said tubular passage-way opening toward said tubular passage, and a direct tubular connection between the lower extremity of said tubular passage and said steam --chamber, substantially as specified.

4. In a water-tube steam-generator, asteamchamber separate from the water-chamber and above the same, a connection between the two, a check-valve in said connection, opening toward the water-chamber, a downward circulatory passage from the waterchamber, and a direct upward passage to the steam-chamber, substantially as specified.

5. In a water-tube steam-generator, a steamchamber separate from the water-chamber, above the same and in communication therewith, a downward circulatory passage from the water-chamberof successively-increasing diameter, a direct upward passage to the steam chamber of uniform diameter, and check-valves to promote downward flow opening from said steam-chamber and said waterchamber respectively, substantially as specified.

' JOHN C. PARKER.

WVitnesses:

HARRY L. HORN, HENRY H. BATES. 

